A cloth piece folding device generally includes multiple conveyors to transfer a cloth piece, and a bending unit to fold the cloth piece being transferred by the conveyors at a given bending position. The bending unit is formed of a bending plate and an actuator to drive the bending plate. The actuator is configured to make the bending plate move forward and backward relative to a connection between two of the conveyors. The bending plate is driven when the bending position of the cloth piece reaches the connection between the conveyors. The bending position of the cloth piece is thrust into the connection between the conveyors and the cloth piece in a folded state is made to enter the connection between the conveyors, thereby folding the cloth piece.
The cloth piece folding device is generally used as a part of a linen facility installed in a laundry factory. As an example, the linen facility is formed of a charger, a roll ironer, and the cloth piece folding device. The input side of the roll ironer is connected to the output side of the charger. The input side of the cloth piece folding device is connected to the output side of the roll ironer. These components form a processing line. A cleaned cloth piece introduced into the charger is placed in a spread state with no loosening. Then, the cloth piece is ironed with the roll ironer and folded by the cloth piece folding device.
Ease of drying changes depending on the type of a cloth piece. Thus, a time for a cloth piece to pass through the roll ironer is adjusted depending on the type of the cloth piece. More specifically, a hard-to-dry cloth piece is set to be transferred at a low speed to take a long time to pass through the roll ironer, thereby drying this cloth piece completely. An easy-to-dry cloth piece is set to be transferred at a high speed to pass through the roll ironer in a short time, thereby enhancing processing efficiency. In this way, a speed of transfer of a cloth piece through the roll ironer is adjusted depending on the type of the cloth piece. A speed of transfer in the cloth piece folding device connected to the roll ironer is also adjusted accordingly in synchronization with the roll ironer.
A conventional cloth piece folding device uses an air cylinder as the actuator of the bending unit (see patent literature 1, for example). The air cylinder is hard to control in terms of an operating speed, so a driving speed of the bending plate is set at a constant speed irrespective of a change in a transfer speed of a conveyor. This makes a speed of a cloth piece being transferred by the conveyor and a driving speed of the bending plate asynchronous with each other, which makes it impossible to fold the cloth piece at the correct bending position, leading to poor folding accuracy.